Cook Biotech Inc., et al. v. ACell, Inc., et al.

At district court (N.D. Ind.), a jury found that ACell’s commercial product infringed U.S. Pat. No. 5,554,389 (the 389 patent) owned by Purdue Research Foundation (PRF) and licensed exclusively to Cook Biotech. On appeal, the CAFC reversed the judgment of infringement upon finding that there was no material factual dispute that the ACell product infringes the 389 patent, literally or under the doctrine of equivalents.

The technology of the 389 patent is related to a tissue graft composition comprising bladder submucosal tissue that can be implanted to replace or support damaged or diseased tissues. Such compositions are know as extracellular matrices or ECMs and are generally used as scaffolds for tissue reconstruction. Dr. Spievack of ACell and Dr. Badylack of Purdue had discussed Dr. Badylack’s work on graft compositions at a conference in which he had presented. Subsequently, the accused product was developed and related technology patented (in a number of patents the CAFC labeled as “Disputed Patents”) by ACell, notably following a rejected request for a license from Purdue.

The issues on appeal are 1) whether ACell infringed the 389 patent, literally or under the doctrine of equivalents, 2) whether Dr. Badylack is also an inventor of the “Disputed Patents”, and 3) whether there was unjust enrichment for the research and inventions disclosed in the Disputed Patents?

Literal Infringement: With respect to literal infringement, the CAFC construed the phrase “the luminal portion of the tunica mucosa” in the 389 patent claims. ACell argued that this term was defined narrowly in another patent, the 508 patent, which was incorporated by reference into the 389 patent. The CAFC agreed, and concluded that the incorporation by reference was evidence of intent to refer to the same structure. “Incorporation by reference provides a method for integrating material from various documents into a host document . . . by citing such material in a manner that makes clear that the material is effectively part of the host document as if it were explicitly contained therein.” “To incorporate material by reference, the host document must identify with detailed particularity what specific material it incorporates and clearly indicate where that material is found in the various documents.” The ACell construction of the term requires a delamination that is not performed with the ACell product. Accordingly, the CAFC found that the ACell product could not literally infringe the 389 patent.

Doctrine of Equivalents: With respect to infringement under the doctrine of equivalents, the CAFC concluded that there was no infringement because the 389 claims specifically excluded an element in the accused product. Under a corollary to the “all limitations rule,” “the concept of equivalency cannot embrace a structure that is specifically excluded from the scope of the claims.”

Inventorship: The CAFC stated that the only evidence argued by Cook/PRF that Dr. Badylak was an inventor was the statement by Dr. Spievack that they had once talked about “the basement membrane stuff.” However, this testimony was insufficient to create a genuine issue of material fact as to whether Dr. Badylack contributed ‘to the conception of the claimed invention that is not insignificant in quality.” This, in combination with an express disavowal by Dr. Badylack as to inventorship, prevented reversal of the summary judgement finding that Dr. Spievack was the only inventor.

Unjust Enrichment: Finally, the CAFC summarily dismissed the unjust enrichment claim, stating that PRF did not present evidence to raise a genuine issue of material fact. Therefore, there was no basis to consider whether a constructive trust was appropriate.